Neon is actually less dense than Nitrogen. According to Wikipedia: Nitrogen..Density at stp (0 °C and 101.325 kPa) : 1.251 g/L Neon......Density at stp (0

Neon is actually less dense than Nitrogen. According to Wikipedia: Nitrogen..Density at stp (0 °C and 101.325 kPa) : 1.251 g/L Neon......Density at stp (0 °C and 101.325 kPa) : 0.9002 g/L Nitrogen has a lower atomic number than Neon, but on the other hand Nitrogen is diatomic, which I imagine accounts for the greater density. Neon is insanely expensive however.